Now includes GDB Server, and supports free Flash breakpoints with NXP LPC microcontrollers!

J-Link Overview

J-Link is a USB-powered JTAG emulator supporting a large number of CPU cores.

Based on a 32-bit RISC CPU, it can communicate at high speed with the supported target CPUs. J-Link is used around the world in tens of thousands of places for development and production (flash programming) purposes.

You can develop your own applications to utilize the entire functionality of J-Link with the J-Link Windows SDK (see below).

J-Link is supported by all major IDEs such as IAR EWARM, Keil MDK, Rowley CrossWorks, Atollic TrueSTUDIO, IAR EWRX, Renesas HEW, Renesas e2studio, and many others. Including all models, more than 100,000 J-Links have been sold so far, making J-Link probably the most popular emulator for ARM cores.

J-Link Features

Direct download into Flash memory of most popular ARM microcontrollers supported

J-Link Software

The following free software is available to download and use with J-Link :

JLink.exe (Command line tool)

JLink.exe is a tool that can be used to verify proper installation of the USB driver and to verify the connection to the ARM chip, as well as for simple analysis of the target system. It permits some simple commands, such as memory dump, halt, step, go and ID-check, as well as some more in-depth analysis of the the state of the ARM core and the ICE breaker module.

J-Link TCP/IP Server (Remote J-Link use)

The J-Link TCP/IP server allows a J-Link to be used remotely via TCP/IP. This enables you to connect to and fully use a J-Link from another computer. Performance is just slightly (about 10%) lower than with direct USB connection.

J-Mem Memory Viewer

J-Mem displays memory contents of ARM-systems and allows modifications of RAM and sfrs (Special function registers) while the target is running. This makes it possible to look into the memory of an ARM chip at run time; RAM can be modified and sfrs can be written. The type of access for both read and write can be selected to be 8/16/32 bit. It works nicely when modifying sfrs, especially because it writes the sfr only after the complete value has been entered.

Flash Loader

A collection of optimized Flash loaders allow you to download into Flash directly from the debugger in the same way as downloading to RAM. The Flash memory can be internal, on-chip Flash memory or external CFI-compliant NOR Flash memory. Taking advantage of J-Link's download speeds up to 720kB/s into RAM, it allows programming the Flash of most common microcontrollers very quickly. Flash sectors which already contain the correct data do not have to be reprogrammed; a fast 32-bit CRC algorithm can be used for verification, making the Flash download process feel as fast as a download to RAM.

GDB Server

The J-Link GDB Server is a remote server for the GDB. The GDB and GDB Server communicate via a TCP/IP connection, using the standard GDB remote serial protocol. The GDB Server translates the GDB monitor commands into commands understood by the J-Link ARM. See the legacy GDB Server order page for details. (The GDB Server license is included with your J-Link purchase at no extra cost.)

Optional Development Support

The J-Link Developer SDK is a standard Windows DLL typically used from C, Visual Basic, Delphi etc. It allows you to create exported functions within your own applications to utilize the entire functionality of the J-Link ARM. This includes things such as halting/stepping the ARM core, reading/ writing CPU and ICE registers, and reading/writing memory. Therefore, it can be used in any kind of application for access to an ARM core. Sample applications are a memory viewer, DCC communication program, Debugger or Flash programming tool. Either version of this DLL may be added to your order using the option boxes at the bottom of this page (or any of the J-Link Bundle pages). Note that the Flash version contains all the features of the standard, so there is no need to check both boxes.

Optional 20-pin to 14-pin Adapter

A 14-pin ARM JTAG Adapter can be used on targets that require it. See the Purchasing Options section below to purchase the adapter at a discount with the J-Link.

Optional Flash Programming Software

The J-Flash ARM software for Windows 2000/XP works with the J-Link ARM and supports all common external Flashes as well as the programming of internal Flash in ARM microcontrollers. It allows you to ERASE, FILL, Program BLANK CHECK, CHECKSUM, UPLOAD Flash content, and VIEW MEMORY functions of the software with your Flash devices. See the Purchasing Options section below to purchase the J-Flash software at a discount with the J-Link.

Optional RDI Support

The J-Link ARM RDI software is an RDI interface for J-Link. It makes it possible to use J-Link with any RDI-compliant debugger. With optional licenses you will be able to set an unlimited number of software breakpoints in Flash memory areas (rather than just the 2 hardware breakpoints), and load your program into Flash for debugging. See the Purchasing Options section below to purchase the RDI Interface or the RDI Pro Bundle (which includes the Flash Breakpoints and Flash Loader licenses) at a discount with the J-Link. (Note: If you're using NXP LPC2000-series ARM7 microcontrollers, no extra purchase is required; the RDI Pro Bundle components are included in the J-Link software free of charge for NXP LPC2000 ARM7 microcontrollers.)

J-Link Purchasing Options

If all you require is the J-Link ARM with or without the Developer DLL, purchase it from this page (use the checkbox at the bottom of this page to select the optional Developer DLL).

However, if you also would like any of the other optional components mentioned above, it is recommended to purchase the J-Link PLUS, which consists of a J-Link with the J-Flash, RDI and Unlimited Flash Breakpoints add-ons at a price cheaper than getting just the J-Link and J-Flash separately, and cheaper than getting the J-Link and RDI support with Unlimited Flash Breakpoints separately. The only combination cheaper than the J-Link PLUS would be to buy this J-Link and the RDI Support add-on separately without the Flash Breakpoints option, but that's only $51 cheaper than the J-Link PLUS, whereas purchasing the J-Link PLUS saves you more than $900 off the price of all those components separately.

See also the J-Link ULTRA+ which provides much faster speeds, lots of add-on software, and a few other features, or the J-Link PRO which provides the ULTRA+'s speeds plus an Ethernet interface and also all the software add-ons.